The present invention relates generally to portable memory and storage devices, and more particularly to a technique to prevent unauthorized access to data on a portable memory or storage device when the portable memory or storage device is removed from an intended information processing device.
Portable memory and storage devices, such as USB memories, PCMCIA memory cards and SD memory cards, are used for transporting or transferring data between computing devices. The portability results from simple detachment from or attachment to suitable computing devices, either by a physical attachment or wireless connection. Because these memory and storage devices are portable, they can be lost or stolen. Consequently, they can fall into the hands of an unintended third party. Therefore, it is desirable to prevent unauthorized access to data on the portable memory or storage device when the portable memory or storage device is removed from an intended information processing device.
In known USB memories, part or all of the memory or storage area is classified as a security area which only an authorized user can access with a proper password. See “PC peripherals: Options by IBM 256 MB USB 2.0 Memory Key” (IBM Japan, Internet URL: http://www-6.ibm.com/jp/pc/option/obi/nob03/22p9025/22p9025a.html, available on Feb. 26, 2004). This document describes a portable memory or storage device where a user must be authenticated through a password before the user can read data stored in a security area. This protects the data from unauthorized access. However, password authentication requires authentication each time the portable memory or storage device is plugged into another information processing apparatus. For example, if the user wants to provide data from his or her personal computer (PC) to another person's PC, the user attaches the portable memory or storage device to his or her PC, writes data on it, detaches the portable memory or storage device from his or her PC, then attaches the portable memory or storage device to the other person's PC, and then must undergo authentication before reading the data on that person's PC. Moreover, because the user enters his or her password on the other person's PC to permit access by this other person, the password may be seen by the other person.
An object of the present invention is to protect a portable memory or storage device from unauthorized access. A more specific object of the present invention is to protect a portable memory or storage device from unauthorized access, in a convenient manner.